PLATE 40 D. 



Fig. 1. 558. 3. Fenestella elegans. (Pag- 164.) 



1 a. A portion of a frond, showing the non-celluliferous side. 



1 6. A portion enlarged, showing the form of fenestrule, striated surface of branches, etc. 



1 c. The impressions of the celluliferous side in the shale. 



1 d. A fragment showing the celluliferous side of the coral. 



1 c. The same enlarged, showing the form and arrangement of the cells. 



1 /. Another specimen of the celluliferous side. 



1 g. The same enlarged, showing the form and appearance of the cells where the surface is somewhat worn. 



Fig. 2. 559. 4. Fenestella tenuiceps. ( Pag. 165.) 



2 a. The exterior surface of a large cyathiform frond which has been crushed. 



2 6. A portion of the last enlarged, showing the cells where the edges of the branches are worn. 



2 6 t- -A- still farther enlargement of 2 6. 



2 c. An enlarged view, looking into the cells from a direction oblique to the surface of the frond. 



2 (1, e. Lateral and basal view of a fragment of the cup broken off just above the root. 



2 /. A specimen showing a fragment of the non-poriferous face of Polypora inccpta and of Fenestelia 



tenuiceps. 

 2 g. A portion of the latter enlarged, showing the form of fenestrules and the granular worn sjirface. 

 2 /(. A portion of another fragment enlarged, showing the striated surface of the branches. 



Fig. 3. 560. 5. Fenestella ckibrosa. (Pag. 166.) 



1 a. A fragment natural size. 3 6. A portion of the same magnified. 



Fig. 4. 561. 6. Fenestella . ( P^g- 166.) 



Fig. 5. 562. 1. Polypora incepta. ( P'lg- 167.) 



5 a. The inner surface of a part of a large frond. 

 5 6. A portion of the same enlarged, showing the striated surface of the branches and the transverse bars. 



5 c. A cup-form .specimen, showing the inner or non-celluliferous surface. 



6 d. The celluliferous face enlarged. 



5 e. The non-celluliferous face enlarged. 



5 /. Several branches from the celluliferous face grcatlj^ enlarged, showing the bifurcation of the branches. 

 and the increasing rows of pores from the point of bifurcation upwards. 



